1. Field of the Invention
The present invention relates to a coordinate inputting apparatus consisting of an information plate and an operating section arranged movably on this information plate and, more particularly, to a coordinate inputting apparatus having a reflection optical system consisting of a light emitting section, an information plate and a light receiving section in which the operating section itself can detect the self movement quantity and moving direction.
2. Description of the Prior Art
Coordinate inputting apparatuses in which the operating section itself detects the self movement quantity and moving direction and supplies the coordinate information to an external information processing apparatus are widespread. This is because such a kind of coordinate inputting apparatuses have various advantages such that the operating efficiency in inputting is extrememly better as compared with a conventional cursor moving key or the like and there is no need to directly reach a long arm toward the screen and operate such as in case of a light-pen, and the like.
Hitherto, as such a kind of coordinate inputting apparatuses, following various kinds of apparatuses have been proposed: an apparatus which detects the movement from the rolling of the ball; an apparatus which derives a coordinate value from a value of a voltage drop due to a resistance; an apparatus using an electromagnetic induction system, etc. However, the apparatuses including a mechanical portion are less than wholly satisfactory in terms of durability and accuracy and most of those apparatuses are large in scale. On the other hand, the voltage drop type and electromagnetic induction type have drawbacks such that they are likely to be influenced by disturbances.